Readings:
" Darwin and Darwinism in Victorian Literature"
by Gary Hentzi Here
"Evolutionary
Psychology: A Primer"
by Leda Cosmides & John Tooby Here
"Evolution
and Literary Theory"
by Joseph Carroll Here
A
wonderful science primer by the novelist
Ian McEwan (from his
Introduction to What We Believe but Cannot Prove) Here
Introduction to Natural
Selection Here
Questions:
Why
does Darwin matter?
What
is evolution?
What
is the theory of Natural Selection (NS) - the process Darwin called
Nature’s weeder?
How on earth does evolution
relate to things like literature and the arts?
***
Why does Darwin
matter?
It’s not
really about Darwin. Whoever hit upon, and published, Natural Selection
first (it was nearly Alfred Wallace) was going to be
famous. NS could have been thought of half a century earlier at least -
it just happened to be CD who put it all together and changed the
world. (The fascinating story of the 1858 Darwin-Wallace paper here)
Darwin matters
because he was the first to show how the complexity, elegance, and
regularity of the biological world could have come about through purely
natural means.
Darwin has become
one of the central figures in science, along with Newton, Galileo,
Einstein and a few others – think of Dan Dennett’s
quote:
If I were to
give a prize for the single best idea anybody ever had, I'd give it to
Darwin for the idea of natural selection. . . His idea unites the two
most disparate features of our universe: The world of purposeless,
meaningless matter-in-motion, on the one side, and the world of
meaning, and purpose, and design on the other.
Tooby and Cosmides
say:
The goal of
Darwin's theory was to explain phenotypic design: Why do the beaks of
finches differ from one species to the next? Why do animals expend
energy attracting mates that could be spent on survival? Why are human
facial expressions of emotion similar to those found in other primates?
But there was a
lot Darwin didn't know. He said nothing about the origin of life (something we still don't know) – only the origin of the many millions of species ("What is a species?" is a question with new import - see Craig Venter
in conversation at Edge.org). He knew nothing about
genes either – which are both the source of variation as well as the
"unit of selection" as Richard Dawkins puts it. Genes also explain the
mechanism of inheritance by which the “recipe of
life” is passed on (Darwin's hypothesis on inheritance - that
it worked via migrating "gemmules" - was hopelessly wrong). He
didn’t even know for sure that the Earth was old enough for
evolution to be a viable explanation (several lerading geologists at the time were suggesting the
earth was only a few tens of millions of years old, at most). Darwin was
also very modest – reluctant to publish - as well as chary of
upsetting his colleagues and ruining his social standing.
OK, so
what is Natural Selection? Click
here to find out
Personalities
in Evolution
- Herbert Spencer (philosopher and one time beau of George Eliot) coined the phrase
"survival of the fittest" to describe NS. But as LSE boffin Rodney Barker explains, Spencer was thinking of the
evolution of human society, not nature:
Like Darwin,
Spencer employed a selective principle to explain social evolution, but
he complemented natural selection with the Lamarckian notion of
adaptation [within a single lifetime], and of the inheritability of a predisposition to successful
adaptation. His familiar phrase, 'the survival of the fittest', can
thus be misleading, in so far as it suggests an arbitrary process
depending on the absence or presence of qualities over which the
individual or society has no control. The fittest were those who
adapted, and there was in principle no limit to the number who might
make this accommodation. The struggle for survival was thus not of man
against man, but of man against a changing environment. Ref
- Francis
Galton (cousin of Darwin) – the "father of eugenics" -
coined the (mistaken) term "for the good of the species" and the
(equally mistaken) phrase "nature versus nurture."
- Darwin
and Freud – both introduced new ideas of
“human nature” – both emphasized the centrality of sex
– sexual selection. Huxley, Spencer etc – these
ideas applied to, and were the property of, all intellectuals, not
merely scientists, much less the narrow domain of biologists. The fragmentation and specialization of knowledge that is
so common within the Academy today was not a feature of
Darwin’s world. cf CP Snow - Two Cultures
Evolutionary psychology is the
idea that brains have evolved just like every other part of an
organism, and that a brain is in effect a collection of specialized
devices that allow an organism to solve certain "domain specific"
problems - in the human case, problems regularly encountered by our
hunter-gatherer ancestors over many thousands of years - things like
methods of navigation, feeding, mating, communication, danger
recognition, environmental exploitation, and emotions (superordinate
programs).
Tooby &
Cosmides say that like structure and behaviour, psychology can also be
considered in terms of its evolutionary history and adaptive potential.
If genes and environments can act as selection pressures, shaping
bodies and behaviours in all sorts of domain-specific ways, why not
brains too? This leads to the inevitable conclusion that males and
females in many lineages - who to some extent face differing,
specific, and recurring challenges - will differ in their psychology
too.
Nevertheless, all
humans share the same basic cognitive architecture, and so all of us
reliably develop a distinctively human set of preferences, motives,
shared conceptual frameworks, emotions, content-specific reasoning
procedures, and specialized interpretation systems—a suite of
skills, or "programs" that often operate beneath the threshold of
consciousness or cultural variability, and which together constitute
what we call “human nature”.
Critique
– “The brain's function is to process
information” – function? Does
that mean it has a purpose? Information? Who
says? Modules? We can posit any module we like - what about the
shoelace-tying module?
Tooby
& Cosmides - 5 principles
1. The brain is an
evolved physical system. It functions as a kind of computer. Its
circuits generate behaviour that is appropriate to environmental
circumstances.
2. Our neural
circuits were designed by natural selection to solve problems that our
ancestors faced during our species' evolutionary history.
3. Consciousness
is just the tip of the iceberg; most of what goes on in your mind is
hidden from you. As a result, your conscious experience can mislead you
into thinking that brain circuitry is simpler that it really is. Most
problems that you experience as easy to solve are actually very
difficult to solve - they require very complicated neural circuitry
– as Andy Clark says, humans are “good at Frisbee,
bad at logic.” Computers tend to be the other way around (so
far).
4. Different
neural circuits are specialized for solving different adaptive
problems. – functional specialization.
5. Our modern
skulls house a mind adapted for the stone age – evolution
works slowly, and adaptations can take a long time to catch up with a
shifting environment – bodies are records of changing
ancestral environments.
Species
– animals can sometimes mate across supposed species
boundaries – mules, whales, crows, gulls – ring
species etc
Copying
– cells copy DNA like computers copy files from one drive to
another. And the fidelity rate of nature is nearly as good as computers
manage. But for one reason or another every now and again a file
doesn’t copy properly, or something unexpected happens. With
computers we toss out the file, but in cells the new goofy copy is now
itself copied, faithfully, and dumbly, unless the mistake renders the
whole machine/organism non-viable.
Sexual
Selection
Surviving is one
kind of problem. Reproducing is often quite another. How do sexual
organisms choose mates? Males and females often have different agendas
when it comes to making reproductive choices. Why do some individuals
fail to find a mate? The tough fact is, if you don't have the right
song, dance, feathers, fur, scent, colours, or whatever - even if you
are fantastic in other ways - then you may be seen by the rest of your
population as defective and thus not sexy. And if you can't get laid,
you don't get to reproduce. And if you don't reproduce you can't be an
ancestor.
Sexual
attractiveness is in some cases synonymous with fitness.
Fitness and
status in humans
The arts and
sciences not only reflect our shared cognitive make up, but works of
art or scientific breakthroughs also serve to reveal something of the
quality of the artist or scientist - which is obviously important when
choosing a mate. And given that artists are often high status
individuals, it's not really surprising that artists have long been
seen as sexy! Ask any rock star... This is one of the arguments made by Geoffrey Miller in his excellent
book The Mating Mind.
Evolutionary
Timeline
c
2,500 BC - Anaximander says life evolved from simple things to more
complicated things. Aristotle later agreed. Neither knew how this evolution might happen.
1790s
- Hutton establishes science of geology - proposes principle of Gradualism - the idea that geologic change is the product of slow, steady,
cumulative processes, and not the result of a few biblical catastrophes.
1794-6 - Erasmus Darwin (Charles's
grandfather) publishes Zoonomia,
or,
the laws of organic life
1798
- Malthus – essay on population economics
1809
– Charles Darwin born - Lamarck suggests inheritance of
acquired characteristics (Erasmus was a fan)
1830 - Charles Lyell –
gradualist geologist & Darwin’s mentor (from about
1840 onwards) suggests world is millions of years old (not thousands)
in his landmark work Principles of Geology. Proposes theory of Uniformitarianism - sometimes
known as "the present is the key to the past." An extension of Hutton's
gradualism, Lyell claims that the processes acting on the
earth today are broadly the same as they have always been.
1831–1836
- Beagle voyage: CD = 22-27 yrs. Earthquake, fossils, Brazil –
wasps - loss of faith, Galapagos birds, Indian ocean coral. CD - who
was ostensibly a geologist - was sent Lyell's Principles midway through the
voyage.
1838
– Darwin reads Malthus essay on population and hits on
natural selection - what he calls "descent with
modification" - but keeps quiet – loss of social
standing was a real threat to a Victorian gentleman – social
unrest in England at the time too – poor laws &
workhouse
1839
– Darwin marries Emma Wedgwood, his first cousin. Keeps his
ideas on evolution semi-secret from her, for a while, on
account of her strong religious beliefs.
1851
– 3rd child Anne dies at age 10 & his remaining
Christian faith is lost
1858
– Wallace writes to Darwin from the island of Ternate (in
Indonesia). The young naturalist has been classifying flora and fauna,
has also recently read Malthus, and while in a malarial fever hit upon
the idea of Natural Selection too. A joint paper is delivered on their
behalf at the Linnaean Society, and the following year CD publishes the Origin
1866 - Gregor Mendel publishes his
seminal paper on genetics. Darwin never read the paper.
1910 - Thomas Hunt Morgan shows that
chromosomes carry genetic information. He also rubbishes the theory of
sexual selection. Darwinism almost drops off the academic agenda - and
is only revived with the work of Haldane, Dobzhansky, and Fisher over
the following decades.
1953 - Watson & Crick (and
Rosalind Franklin, and others), show that the structure of DNA is a
double helix. The mechanics of nuclear replication is revealed.
1978 - Louise
Brown, the world's first "test tube baby" is born with the aid of in vitro fertiization. First genetically modified organism (E.
coli) developed.
1987 - First
criminal conviction as a result of DNA
fingerprinting
1990 - US-UK
effort to map the human genome begins. It is expected to take decades.
1992
- First GM crops produced.
1996 - Birth of
Dolly the sheep, the world's first cloned mammal.
2000 - First
draft of the human genome.
2006 - Human
genome is completely mapped.
Links
First and foremost
- the alternatives to Darwin's theory. The main rivals to Natural
Selection are the so-called Intelligent Design theories. These
"theories" (what is a theory?) all claim that
many structures observed in nature are simply too complicated to have
evolved through natural selection, and that therefore an intelligent
agent - presumably a deity - must have been involved. Chief among these
theories is the belief that the world and everything in it was created
by the Flying
Spaghetti Monster. Press story here. It should be noted that Darwin himself dealt with this objection when he answered William Paley's ssertion that if you come across a watch (clearly designed and built) you don't assume that it came about naturally. Richard Dawkins devoted a book to explaining Paley's mistake.
The
Creationist-Evolutionist argument - http://www.talkorigins.org/ and here
Islam
and Darwinism - here
Consider
the story of the Large Blue Butterfly, then see if
so-called intelligent design makes any sense
Richard Dawkins on why so-called Intelligent Design really isn't so smart - here and here (with Jerry Coyne)
Darwinian
Links
Comprehensive
Darwin site - http://web.clas.ufl.edu/users/rhatch/pages/02-TeachingResources/readingwriting/darwin/05-DARWIN-PAGE.html
The Origin online: http://www.literature.org/authors/darwin-charles/the-origin-of-species/
Natural
Selection - http://en.wikipedia.org/wiki/Natural_selection
Sexual
Selection - http://www.zoology.ubc.ca/~otto/PopGen500/Discussion3/Overheads.html
Mark
Ridley's site - http://www.blackwellpublishing.com/ridley/
BBC
Evolution website - http://www.bbc.co.uk/education/darwin/
Darwin-Wallace
Papers - http://www.origins.tv/darwin/darwin.htm
Darwin@LSE
- readings and papers - http://www.lse.ac.uk/collections/darwin/readings/index.htm
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